Structures in the shape of a hollow hemispherical dome have been proposed and a few such structures have been built. One such recognized name in this art is that of R. Buckminster Fuller. Fuller is the holder of U.S. Pat. No. 2,682,235. U.S. Pat. No. 2,682,235 shows a building structure of generally spherical shape and comprising a framework of interconnected struts arranged in the pattern of a spherical icosahedron. Struts of various lengths are required.
U.S. Pat. No. 3,359,694 to Hein shows a building structure in the shape of a dome of generally hemispherical shape and comprising a plurality of panels of different shapes which form the exterior wall of the dome.
U.S. Pat. No. 3,995,329 to Hannula also shows a building structure in the shape of a hollow dome which may be hemispherical. The dome wall is formed of a plurality of structural cells most of which are square (some are in the shape of an isosceles triangle) and thin in the radial direction of the sphere. The cells are arranged in horizontal rows. A problem with the structure shown in this patent is that the size of the cells must decrease to correspond to the diminishing circumferences of the individual horizontal rows as one goes away from the equator toward the top of the sphere. (The same is true as one goes away from the equator downwardly in those situations where a given dome comprises more than one-half of a sphere).
Other domed building structures are shown in U.S. Pat. No. 3,485,000 to Fiquet, and U.S. Pat. No. 3,691,704 to Novak. U.S. Pat. No. 4,715,160 to Romanelli shows a set of standardized structural elements and accessories which may be used to erect either a "spatial" or a flat structure.
The hemispherical dome building structure appears to have become more an object of fascination than of practical realization. Relatively few such structures have been built. It is believed that the inherent disadvantages of the hollow generally spherical dome structures known to date has been a major reason for this. For instance, the structure of the Hannula patent cited above requires cells of different sizes, which is a major complication in a building structure that is assembled on site.